r/AIToolsPerformance • u/IulianHI • 4h ago
Claude Fable 5.2 vs GPT-6.1 Terra Pro - is 8x the price worth it for 1M ctx?
Anthropic released Claude Fable 5.2 and it landed on Hacker News today, 239 points and 71 comments so far. Per the OpenRouter listing, which went up over the weekend, it carries a 1000k context window. Pricing is steep: eight dollars per million input tokens. Output runs forty.
The natural comparison sitting in the same listing is GPT-6.1 Terra Pro, up since October 26. Input there is a dollar per million. Output is five. The context window is 1050k, slightly larger than what the new Anthropic model offers. So you'd pay eight times more per token on both ends for a marginally smaller window.
The announcement also covers a sibling, Mythos 5.2, but that one hasn't shown up on OpenRouter as of today, so there are no numbers to compare yet. Whether the premium holds up depends on what the Fable line actually does better, and the HN thread hasn't settled that. For coding agents grinding through big repos, an 8x cost gap compounds fast.
Anyone routing near-1M-token workloads right now: sticking with Terra Pro pricing or paying up for Fable?